High strength, combustion-resistant, tube-extrudable aircraft-grade magnesium alloy

1 . A magnesium-based extrusion alloy composition comprising, by weight:

7.0%-11.0% Al, 0.1%-0.8% Zn, 0.15%-0.65% Mn, more than 0.63% Ca, less than 0.56% Y and a balance of Mg and unavoidable impurities; and

wherein a total combined content of said Al, Ca, and Y does not exceed 11 wt % of said alloy; and

wherein said alloy comprises Ca in the form of intermetallic particles;

wherein said intermetallic compounds of Ca and Y comprise: Mg—Al—Ca compounds and Al—Mn—Y compounds, respectively;

wherein said Ca and Y intermetallic compounds contribute to flammability resistance of wrought products made from said alloy;

wherein said intermetallic particles are formed in a wrought process, including extrusion, rolling, or forging;

when said alloy is provided in a matrix phase, said intermetallic particles making up said alloy have an average diameter of 10 μm or less;

said alloy comprises Ca intermetallic particles and said intermetallic particles make up between 1.0% to 5.0% of said alloy by volume; and

said magnesium-based extrusion alloy composition is a forged or drawn alloy that has a yield strength of at least 170 MPa, an ultimate tensile strength of at least 280 MPa and an elongation of at least 7% in tube forms.

2 . The alloy according to claim 1 wherein:

a content of said Mn is between 0.15 wt % to 0.3 wt % of said alloy.

3 . The alloy according to claim 1 wherein:

a content of said Zn is between 0.1 wt % to 0.35 wt % of said alloy.

4 . The alloy according to claim 1 wherein:

a content of said Al is between 8.3 wt % to 10 wt % of said alloy.

5 . The alloy according to claim 1 wherein:

said Ca and said Y are provided in intermetallic compounds.

6 . The alloy, according to claim 1 , wherein:

said Mg—Al—Ca intermetallic compound comprises:

up to 57 wt % Al and up to 43 wt % Ca.

7 . The alloy, according to claim 1 , wherein:

said Al—Mn—Y intermetallic compound comprises 40 wt % Al, 40 wt % Mn and 20 wt % Y.